Method and Apparatus for Creating Patterns in Dyed Textiles by Water-Jet Treatment

ABSTRACT

The invention relates to a method for creating patterns on dyed materials ( 1 ), comprising the following steps: a continuous length of a dyed material ( 1 ) of a predetermined width is transported on a support element ( 2 ) in a machine direction with a selected web speed; at least one jet distributor is provided above the dyed material ( 1 ) that is transported on the support element ( 2 ), said distributor producing columns or bars of fluid jets ( 4 ), which are produced with a selected distributor pressure and spray onto the opposing face of the dyed material ( 1 ) that is transported on the support element ( 2 ); the fluid jets ( 4 ) strike the opposing face of the dyed material ( 1 ) whilst the latter is transported on the support element ( 2 ) in the direction of the machine; the fluid jets ( 4 ) traverse the defined openings ( 6 ) of a template ( 5 ) before striking the opposing face of the dyed material ( 1 ).

The invention relates to a method and an apparatus for creating patterns in dyed textiles.

For a number of textile products, a visible pattern or other pattern effect is produced on the finished fabric. For dyeing and color printing, additive processes are often carried out in which dyes or pigments are added to undyed or previously dyed textile products. A subtractive process is also possible for removal of color from a previously dyed textile product. Various subtractive processes for treatment of dyed textile products are known in this field that, however, have various disadvantages. For example, discharge printing is a subtractive printing method in which a previously dyed textile product is imprinted with a paste of sodium hydroxide or sodium hydrogen sulfite to eliminate the color in the previously printed areas. The etching paste used may cause severe damage to the textile product if it is not carefully washed off afterward. Another chemically induced subtractive process is acid washing, in which the color is removed from a textile product that has already been processed into a clothing article. In acid washing, pumice stones are soaked in chlorine bleach and then added to a load of clothing articles in an industrial washing machine not containing water. The load of stones and clothing articles is agitated for a long period of time, and the effect of the acid combined with the abrasion from the stones achieves the desired degree of decolorization that, however, may be extremely disadvantageous for the strength and durability of the textile.

A purely mechanical, color-subtractive process is provided when stone washing is performed without the addition of acid. In this case the decolorization results strictly from friction, abrasion, and lack of wash fastness of the color. In stone washing the textile product is subjected to less wear and damage than in acid washing. In both cases, however, the washout patterning of the textile product cannot be precisely controlled, and is not reproducible with consistent quality when performed repeatedly.

These methods also represent a great environmental burden when chemical substances are used in the subtractive patterning of textiles.

In light of the foregoing, methods have been developed for subtractive patterning of fabrics by treatment with a nonetching fluid that does not create damage and wear on the production equipment, and does not harm the textile products.

One example of an apparatus and a method for wet patterning of textile products is described in EP 0,459,976 [U.S. Pat. No. 5,737,813]. A web of a textile product is transported through a patterning station, the conveyor including a support surface that is provided with a pattern of solid areas and void areas interspersed therein. The textile product is placed flat in contact with the support surface as it is transported through the patterning station. Water jets form a fluid curtain that is directed downward against the textile product while it is moved through the patterning station on the support surface. The water jets impact the textile product and the patterned surface situated therebelow, such that a visual property of the textile product is altered corresponding to the pattern of solid and void areas on the support surface.

A further method and apparatus for striped patterning of dyed fabrics by water jet treatment are disclosed by EP 1 012 369.

Described therein is an improved technique for creating a striped pattern on a dyed material by water jet treatment. Striped patterns are created without a support surface, provided with patterning, beneath the fabric. Striped patterns having strong contrasts and improved clarity may be produced in this manner. In addition, different striped patterns may be easily and economically created without the use of pattern-directed nozzles.

A disadvantage of the previously known methods and apparatuses for creating patterns in dyed fabrics by water jet treatment is that either the quality of the patterning is reduced, or the design is limited to stripes.

The object of the present invention is to provide a method of and an apparatus for creating patterns in predyed fabrics by means of water jet treatment that allows a large number of patterns of high quality.

The object is achieved according to the invention by use of a method according to claim 1, and a corresponding apparatus.

Advantageous embodiments are the subject matter of the subclaims.

The method for creating patterns in dyed textiles comprises the following steps: a continuous length of a dyed material having a predetermined width, i.e., a textile web, is transported on a support element in a machine direction at a predetermined travel speed. The term “textile” includes woven fabrics, knitted fabrics, and bonded nonwoven fabrics. At least one nozzle array is provided above the dyed textile that is transported on the support element, columnar jets or a liquid jet curtain generated at a predetermined distributor pressure being sprayed onto a confronting face of the textile that is transported on the support element. The liquid jet or jets strike the confronting face of the textile while the textile is transported on the support element in the machine direction. A special feature in this method is the step in which the liquid jets pass through defined openings in a template before being sprayed downward on the confronting face of the textile. The liquid jets from the nozzle array strike the dyed textile only in the region of the openings in the template, and the dye is washed out from the dyed textile only in the region of the openings. The fabric thus acquires a light coloration at these locations. As the result of the specialized design of the openings in the template, any given pattern may be created on a textile, for example a jeans textile, by washing out.

In one preferred embodiment of the method, the template comprises a continuous belt. In a further advantageous embodiment the template is designed as a drum made of metal or plastic. In both cases the template rotates about a horizontal axis that extends transverse to the direction of the web velocity.

The support element may also be designed as a continuous belt. Such continuous belts run over multiple cylindrical rollers, for example.

Below the dyed textile impacted by water, the dyed textile may be transported by a support element designed as a screen belt. The water that seeps through it is preferably collected in gutters or is drawn off by suction boxes.

The nozzle array is provided with outlet openings from which, depending on the shape, water jets are emitted in the form of columns or curtains. Water is fed under high pressure into the nozzle array by means of suitable high-pressure pumps.

One illustrated embodiment of the invention is explained below with reference to the FIGS. that show the following:

FIG. 1 shows an apparatus according to the invention for creating heart-shaped patterns on a textile web 1, a template 5 being designed as a belt. The belt runs over four cylindrical rollers 9 as a continuous belt having defined openings 6 in the form of small hearts. The dyed textile 1 is transported from left to right in the direction of the arrow between support element 2 that runs on two additional cylindrical rollers 3, and the belt template 5, while columns of liquid jets 4 emitted from above from outlet openings 8 in a nozzle array (not illustrated) strike the textile web 1 perpendicularly through the openings 6 in the template 5. A suction box 7 is located below the outlet openings 8 and the support element 2;

FIG. 2 shows an apparatus according to the invention for creating heart-shaped patterns on a textile web 1, the template 5 being designed as a drum. Shown as the pattern are small hearts that are recognizable on the textile 1 as regions 10 of washed-out color;

FIG. 3 shows an apparatus according to the invention in which the dyed textile 1 is transported in an arcuate path between the template 5 and the support element 2, in the direction of the arrow;

FIG. 4 shows an apparatus according to the invention in which the support element 2 is designed as a continuous belt and is moved by three rollers 3 in the direction of the arrow; and

FIG. 5 shows a further variant analogous to FIG. 4 in which the support element 2 is designed as a continuous belt and is moved by three rollers 3.

LIST OF REFERENCE NUMERALS

-   1 Dyed textile -   2 Support element -   3 Roller -   4 Liquid jets -   5 Template, drum; continuous belt -   6 Opening -   7 Suction box -   8 Outlet opening -   9 Roller -   10 Color contours 

1-8. (canceled)
 9. A method of patterning a dyed textile web, the method comprising the steps of: passing the dyed textile web continuously in a predetermined travel direction through a patterning station; supporting the web in the station on a support element; directing from a nozzle array at least one water jet at the web in the station on the element; and interposing between the nozzle array and the web in the station a template having at least one pattern hole so as to intercept at least a portion of the water jet such that the water jet only impinges a predetermined region of the web and washes dye out of the web at this region.
 10. The patterning method defined in claim 9 wherein the template is endless and is formed with an array of holes, the method further comprising the step of continuously moving the template between the nozzle array and the web.
 11. The patterning method defined in claim 10 wherein the template and web are moved in the same direction.
 12. The patterning method defined in claim 9 wherein the support is underneath the web and the jet is directed downward at the web.
 13. The patterning method defined in claim 12 wherein the array emits a plurality of jets in a row extending transverse to the travel direction.
 14. The patterning method defined in claim 9, further comprising sucking water from jets through the web by a suction box forming the support element.
 15. An apparatus for patterning a dyed textile web, the apparatus comprising: conveyor means for transporting the dyed textile web continuously in a predetermined travel direction through a patterning station; a support element underneath the web in the station; a nozzle array having at least one water jet directed at a the web in the station on the element; and a template interposed between the nozzle array and the web in the station and having at plurality of small pattern holes so as to intercept at least a portion of the water jet such that the water jet only impinges a predetermined region of the web and washes dye out of the web at this region.
 16. The patterning apparatus defined in claim 15 wherein the jet includes a row of nozzles extending transverse to the direction, directed downward, and each emitting a respective such water jet. 